1. Field of the Invention
The present invention relates to a process of formation of multiple centers of cartilage and bone induction and more particularly to a process of preparing organic bone matrix by forming artificial perforations, in the form of continuous channels, therein which perforations become centers of cartilage and bone induction after the implantation of said organic bone matrix, and to product, such as the artificially perforated organic bone matrix, obtained by the process taught herein. The invention involves forming multiple artificial perforations having the form of continuous channels in organic bone matrix prior to said organic bone matrix surgical implantation in order to produce formation of multiple centers of cartilage and bone induction after the implantation of same and to produce a significant increase in the ability of the implanted material to induce cartilage and bone formation.
2. Description of the Prior Art
As is known, bones and teeth are composed of a matrix of organic material consisting of collagenous fibrils and a binding substance of mucopolysaccharides as well as of the inorganic component, namely calcium phosphate in the form of hydroxyapatite. The organic matrix is formed by filiform molecules arranged parallel to each other. Furthermore, the tissue is transversed by numerous microscopic capillaries which are oriented in various directions to said filiform molecules.
It is known that if the inorganic component is partially or completely removed from the bone or tooth, the remaining organic bone material, called organic bone matrix, can be transplanted to other living animal or human bodies without substantial deleterious effects. Consequently, bone matrix is used in modern medical procedures for its ability to induce formation of cartilage and bone after its implantation into a body site (this phenomena is known as "osteoinduction").
While the prior art has recognized the need for methods to stimulate osteoinduction and for material with augmented ability to induce cartilage and bone formation, none have disclosed the unique process of the herein disclosed invention.
Myers, et al. Pat. No. 3,458,397 is directed to a process for producing osteogenic material from animal bone tissue. The osteogenic material is injected into an animal for the purpose of inducing bone formation. In this process, the bone is comminuted with pepsin in an acid solution and then digested, extracted and precipitated. There is no suggestion in this reference, however, of artificially perforating the bone matrix as is taught herein.
Urist Pat. No. 4,294,753 is directed to a bone morphogenetic protein process for separating proteins from bone tissue. As in the previous reference, this reference calls for a comminution of the bone and the demineralization of the bone tissue The demineralized bone tissue is then treated in an aqueous solution with a water soluble, neutral salt and a solubilizing agent. The neutral salt and the solubilizing agent are then separated, and the bone morphogenetic protein is precipitated. Once again, no mention of any type of perforation in the produced substance is shown.
Sano Pat. No. 2,621,145 is directed to bone mat compositions and includes particulates of bone which are then enmeshed in a fibrin network. This produces a bone mat which is supported on a carrier strip stated to be of a flexible, plastic material. The process taught in this reference produces a flexible strip for use in bone surgery and promoting the regrowth of bone and includes what is termed a plurality of unboiled particles of ground, whole bone enmeshed in a fibrin network. This reference does not provide for perforating the bone mat composition or fibrin network as is taught herein.
Rapkin Pat. No. 2,968,593 describes a method of preparing inorganic bone material by heating animal bone material in a liquid to a temperature from about 80.degree. C. to about 100.degree. C., drying the heated bone material, substantially defattening it wih a fat-extracting solvent, and removing the organic matrix from the defattened bone material, for instance, by extraction with ethylene diamine to obtain the inorganic matrix. Such an inorganic bone material which is free of organic matter is used for transplantation from an animal of one species to another species without any adverse effect. However, there is no provision taught in the reference for perforating the inorganic bone material so produced.
Thiele, et al. Pat. No. 4,172,128 is directed to a process of degrading/regenerating bone and tooth material. This reference provides a method of making a bone material which is implanted into an area to stimulate bone growth. In this reference the bone material is first ground and then the organic matrix of the bone is demineralized. A colloidal solution of the organic matrix is formed and ions are caused to diffuse into the colloidal solution in order to form a gel. Although the substance created through this process appears to be used for osteogenesis, this reference does not provide for perforating said substance as is taught herein.
Koster et al Publication Langenbecks Archiv fur Chirurgie v. 341, p. 77-86, 1976 described ceramic bone implants with various Ca/P ratio and pores that do not extend through the implant. After this ceramic is implanted into bone defects it demonstrates bone ingrowth (the bone sprouting from the fracture ends grows inside the ceramic channels) and the ceramic becomes gradually resorbed. This reference does not teach about the process for the formation of multiple centers of cartilage and bone induction, neither does it teach about organic bone matrix with multiple perforations in the form of continuous channels which perforations become individual centers of cartilage and bone induction (cartilage and bone are formed de novo without any connection to previously existing sources of cartilage or bone).